Investigating the dynamic regulation of PRMT5 activity during the DNA damage response.

The DNA damage response is essential for maintaining genome stability and the prevention of diseases such as cancer and neurodegeneration. Post-translational modification of proteins is critically required for all types of DNA repair, and whilst this is well appreciated for ubiquitylation and phosphorylation, little is known about the importance of arginine methylation. We have recently shown that PRMT5, an enzyme that catalyses arginine methylation, is critical for double strand break repair via the methylation of RUVBL1 (Clarke et al Molecular Cell, 2017)). Interestingly, we have shown that the methylation of RUVBL1 is rapidly induced after DNA damage suggesting that PRMT5 activity is dynamically regulated in a context specific manner. Surprisingly, very little is known about how PRMT5 directs specific substrate methylation after a particular stimulus. Moreover, unlike lysine methylation, the identity of the in vivo arginine demethylase still remains elusive.
Using unique tools that the Davies lab has generated, this PhD project will further investigate the modulation of PRMT5 activity by post-translational modification downstream of DNA damage signalling, and utilise a CRISPR screen in conjunction with a custom epigenetic arrayed gRNA library to identify novel arginine demethylases. Methodologies used to address these questions will include protein biochemistry, enzyme assays, immunoblotting, appropriate cell biology assays, microscopy, CRISPR gene knockout and RNA interference in human cancer cell lines and mass spectrometry.